CAREER: Biogeochemical Modification of Seawater CO2 Chemistry in Near-Shore Environments: Effect of Ocean Acidification

由于众所周知的化学原理，可以非常准确地预测由于大气中二氧化碳含量上升而导致的公海海水中二氧化碳化学性质的变化。 另一方面，在近岸环境中，这些预测要困难得多，因为二氧化碳的化学性质在很大程度上受到以小时至数月为时间尺度的地球化学过程的影响。 为了预测近岸海水CO2化学将如何响应海洋酸化（OA）而发生变化，关键是要考虑净生态系统生产（NEP）和净生态系统钙化（NEC）的相对影响，以及这些过程如何响应这一重大扰动而发生变化。 在最近于2011年1月举行的关于海洋酸化对海洋生物和生态系统影响的IPCC第二工作组/第一工作组研讨会上，以及2012年6月在西雅图举行的国际海洋酸化网络研讨会上，了解未来海洋酸化将如何改变近岸海水CO2化学和变异性被确定为一个主要的关键知识差距。 从这个CAREER奖的资金，在斯克里普斯海洋研究所的研究人员和他的学生将研究如何生物地球化学过程和NEP和NEC的相对贡献修改海水CO2化学在近岸环境的影响下，不同的底栖生物群落在良好的表征环境和物理条件下，以及这些过程可能会改变响应OA。 该小组将调查亚热带地区数量有限的对比栖息地，（礁顶、礁背/礁斑、泻湖、海草床、藻垫）和温带（海藻床、潮间和潮下、沼泽）环境，采用基于总溶解无机碳（DIC）变化的化学计量矢量方法评估系统碳循环的功能和性能的方法，总碱度（TA）。 这些实地研究将辅之以在不同的有机酸情景下进行对照和混合底栖生物群落的受控围隔生态系统实验。 该项目有两个教育组成部分：（1）开发一个基于探究、体验和协作学习的研究驱动的开放存取和地球化学课程;以及（2）与海洋探索研究所（ODI）合作，通过以OA为重点的教育活动，让来自当地代表性不足的少数民族社区的个人参与科学，并为高中生和大学生提供适量的实习机会，让他们从事这项研究项目。 更广泛的影响：该项目将直接支持一名博士生，一名初级研究技术员，以及两名高中和大学实习生，他们来自代表性不足的少数民族（URM）。 它将有助于80名本科生和研究生参加海洋酸化/海洋地球化学研究课程的教育，该课程在SIO/UCSD整个项目期间提供四次。 关于OA主题的教育和课程材料，包括动手实验室，课堂和实地活动，将通过与ODI的合作开发，并在城市高地地区，一个贫困和种族多样性最高的社区，带给数百名URM学生和他们的老师。 这种合作将使URM学生直接参与在本地和全球范围内具有高度相关性的快速发展的研究领域。 为了确保该项目和OA主题的广泛传播，研究团队将与Google Ocean团队合作，将信息和教育材料整合到Google Ocean Explorer中。

Because of well-known chemical principles, changes in the CO2 chemistry of seawater in the open ocean as a result of rising atmospheric CO2 can be predicted very accurately. On the other hand, in near-shore environments, these projections are much more difficult because the CO2 chemistry is largely modified by biogeochemical processes operating on timescales of hours to months. To make predictions on how near-shore seawater CO2 chemistry will change in response to ocean acidification (OA), it is critical to consider the relative influence of net ecosystem production (NEP) and net ecosystem calcification (NEC), and how these processes might change in response to this major perturbation. Understanding how future OA will alter near-shore seawater CO2 chemistry and variability was identified as a major critical knowledge gap at the recent IPCC WG II/WG I workshop on impacts of ocean acidification on marine biology and ecosystems in January of 2011, and also at the International Ocean Acidification Network workshop in Seattle in June of 2012. With funding from this CAREER award, a researcher at the Scripps Institute of Oceanography and his students will study how biogeochemical processes and the relative contributions from NEP and NEC modify seawater CO2 chemistry in near-shore environments influenced by different benthic communities under well characterized environmental and physical conditions, and how these processes might change in response to OA. The team will investigate a limited number of contrasting habitats in subtropical (reef crest, back/patch reef, lagoon, seagrass bed, algal mat) and temperate (kelp bed, inter- and sub-tidal, marsh) environments during summer and winter, employing a method that evaluates the function and performance of the carbon cycle of a system using a stoichiometric vector approach based on changes in total dissolved inorganic carbon (DIC) and total alkalinity (TA). These field studies will be complemented by controlled mesocosm experiments with contrasting and mixed benthic communities under different OA scenarios. The project has two educational components: (1) developing a research-driven OA and biogeochemistry course based on inquiry-, experience-, and collaborative-based learning; and (2) working with the Ocean Discovery Institute (ODI) to engage individuals from a local underrepresented minority community in science through educational activities focused on OA, and also providing a moderate number of internships for high school and college students to engage in this research project. Broader Impacts: This project will directly support one PhD student, one junior research technician, and two high school and college interns from underrepresented minorities (URM) each summer of the project. It will contribute to the education of 80 undergraduate and graduate students participating in the research based ocean acidification/biogeochemistry course offered four times throughout the duration of the project at SIO/UCSD. Education and curricular material on the topics of OA, including hands-on laboratories, classroom and field-based activities will be developed through the collaboration with the ODI and brought to hundreds of URM students and their teachers in the City Heights area, a community with the highest poverty and ethnic diversity in the San Diego region. This collaboration will enable URM students to directly engage in a rapidly evolving field of research that has high relevance at both the local and global scales. To ensure broad dissemination of this project and the topic of OA, the research team will work with the Google Ocean team to incorporate information and educational material in the Google Ocean Explorer.